RESUMO
As curative therapies for pediatric AML remain elusive, identifying potential new treatment targets is vital. We assessed the cell surface expression of CD74, also known as the MHC-II invariant chain, by multidimensional flow cytometry in 973 patients enrolled in the Children's Oncology Group AAML1031 clinical trial. 38% of pediatric AML patients expressed CD74 at any level and a comparison to normal hematopoietic cells revealed a subset with increased expression relative to normal myeloid progenitor cells. Pediatric AML patients expressing high intensity CD74 typically had an immature immunophenotype and an increased frequency of lymphoid antigen expression. Increased CD74 expression was associated with older patients with lower WBC and peripheral blood blast counts, and was enriched for t(8;21), trisomy 8, and CEBPA mutations. Overall, high CD74 expression was associated with low-risk status, however 26% of patients were allocated to high-risk protocol status and 5-year event free survival was 53%, indicating that a significant number of high expressing patients had poor outcomes. In vitro pre-clinical studies indicate that anti-CD74 therapy demonstrates efficacy against AML cells but has little impact on normal CD34+ cells. Together, we demonstrate that CD74 is expressed on a subset of pediatric AMLs at increased levels compared to normal hematopoietic cells and is a promising target for therapy in expressing patients. Given that nearly half of patients expressing CD74 at high levels experience an adverse event within 5 years, and the availability of CD74 targeting drugs, this represents a promising line of therapy worthy of additional investigation.
RESUMO
BACKGROUND: Detection of measurable residual disease detection (MRD) by flow cytometry after the first course of chemotherapy is a standard measure of early response in patients with acute myeloid leukemia (AML). Myeloid leukemia associated with Down Syndrome (ML-DS) is a distinct form of AML. Differences in steady-state and regenerating hematopoiesis between patients with or without DS are not well understood. This understanding is essential to accurately determine the presence of residual leukemia in patients with ML-DS. METHODS: A standardized antibody panel defined quantitative antigen expression in 115 follow-up bone marrow (BM) aspirates from 45 patients following chemotherapy for ML-DS or DS precursor B-cell acute lymphoblastic leukemia (B-ALL-DS) with the "difference from normal (ΔN)" technique. When possible, FISH and SNP/CGH microarray studies were performed on sorted cell fractions. RESULTS: 93% of BM specimens submitted post chemotherapy had a clearly identifiable CD34+ CD56+ population present between 0.06% and 2.6% of total non-erythroid cells. An overlapping CD34+ HLA-DRheterogeneous population was observed among 92% of patients at a lower frequency (0.04%-0.8% of total non-erythroid cells). In B-ALL-DS patients, the same CD34+ CD56+ HLA-DRheterogeneous expression was observed. FACS-FISH/Array studies demonstrated no residual genetic clones in the DS-specific myeloid progenitor cells. CONCLUSIONS: Non-malignant myeloid progenitors in the regenerating BM of patients who have undergone chemotherapy for either ML-DS or B-ALL-DS express an immunophenotype that is different from normal BM of non-DS patients. Awareness of this DS-specific non-malignant myeloid progenitor is essential to the interpretation of MRD by flow cytometry in patients with ML-DS.
Assuntos
Linfoma de Burkitt , Síndrome de Down , Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Humanos , Medula Óssea/patologia , Síndrome de Down/diagnóstico , Síndrome de Down/metabolismo , Citometria de Fluxo/métodos , Leucemia Mieloide Aguda/patologia , Células-Tronco Hematopoéticas/metabolismo , Antígenos CD34/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Neoplasia Residual/diagnóstico , Neoplasia Residual/metabolismo , Linfoma de Burkitt/metabolismo , ImunofenotipagemRESUMO
Mycobacterium tuberculosis (M.tb), a bacterial pathogen that causes tuberculosis disease (TB), exerts an extensive burden on global health. The complex nature of M.tb, coupled with different TB disease stages, has made identifying immune correlates of protection challenging and subsequently slowing vaccine candidate progress. In this work, we leveraged two delivery platforms as prophylactic vaccines to assess immunity and subsequent efficacy against low-dose and ultra-low-dose aerosol challenges with M.tb H37Rv in C57BL/6 mice. Our second-generation TB vaccine candidate ID91 was produced as a fusion protein formulated with a synthetic TLR4 agonist (glucopyranosyl lipid adjuvant in a stable emulsion) or as a novel replicating-RNA (repRNA) formulated in a nanostructured lipid carrier. Protein subunit- and RNA-based vaccines preferentially elicit cellular immune responses to different ID91 epitopes. In a single prophylactic immunization screen, both platforms reduced pulmonary bacterial burden compared to the controls. Excitingly, in prime-boost strategies, the groups that received heterologous RNA-prime, protein-boost or combination immunizations demonstrated the greatest reduction in bacterial burden and a unique humoral and cellular immune response profile. These data are the first to report that repRNA platforms are a viable system for TB vaccines and should be pursued with high-priority M.tb antigens containing CD4+ and CD8+ T-cell epitopes.
RESUMO
Given the popularity of ketogenic diets, their potential long-term consequences deserve to be more carefully monitored. Mitochondrially derived formate has a critical role in mammalian one-carbon (1C) metabolism and development. The glycine cleavage system (GCS) accounts for another substantial source for mitochondrially derived 1C units. OBJECTIVE: We investigated how the ketogenic state modulates mitochondrial formate generation and partitioning of 1C metabolic fluxes. DESIGN: HepG2 cells treated with physiological doses (1 mM and 10 mM) of ß-hydroxybutyrate (ßHB) were utilized as the in vitro ketogenic model. Eight-week male C57BL/6JNarl mice received either a medium-chain fatty-acid-enriched ketogenic diet (MCT-KD) or a control diet AIN 93M for 8 weeks. Stable isotopic labeling experiments were conducted. RESULTS AND CONCLUSIONS: MCT-KD is effective in weight and fat loss. Deoxythymidine (dTMP) synthesis from the mitochondrial GCS-derived formate was significantly suppressed by ßHB and consumption of MCT-KD. Consistently, plasma formate concentrations, as well as the metabolic fluxes from serine and glycine, were suppressed by MCT-KD. MCT-KD also decreased the fractional contribution of mitochondrially derived formate in methionine synthesis from serine. With the worldwide application, people and medical professionals should be more aware of the potential metabolic perturbations when practicing a long-term ketogenic diet.
Assuntos
Dieta Cetogênica , Ácido 3-Hidroxibutírico/metabolismo , Animais , Carbono/metabolismo , Dieta Cetogênica/métodos , Humanos , Corpos Cetônicos/metabolismo , Masculino , Mamíferos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Serina/metabolismo , Triglicerídeos/metabolismoRESUMO
The role of allopurinol usage in colorectal cancer (CRC) has no definite conclusion. The aim of this study was to explore the correlation between allopurinol usage and CRC risk in Taiwan. Using the National Health Insurance Database, we conducted a case-control study of cases who were ≥20 years old and had newly diagnosed CRC for the period from 2000 to 2013. The controls were matched to cases by age, sex, index year, comorbidities, and socioeconomic status using propensity scores. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were measured by the conditional logistic regression model. We examined 4372 cases and 4372 matched controls. A statistically significant correlation was noted between allopurinol usage and CRC risk (OR, 0.79; 95%CI, 0.69-0.90). We used the cumulative-defined daily doses (cDDDs) in a further subgroup analysis, the ORs decreased from tertile 1 (T1; low dose, <12 cDDDs), T2 (medium dose, 12 to 88.5 cDDDs), to T3 (high dose, >88.5 cDDDs). These values were 0.85 (95%CI, 0.69-1.06), 0.77 (95%CI, 0.62-0.95), to 0.76 (95%CI, 0.61-0.94). The results indicated a dose-response relationship between allopurinol usage and CRC risk (P for trend < .001). We thus inferred that patients with medium and high doses of allopurinol (≥12 cDDDs) had a statistically significantly decreased CRC risk.
Assuntos
Alopurinol/administração & dosagem , Neoplasias Colorretais/epidemiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Estudos de Casos e Controles , Comorbidade , Relação Dose-Resposta a Droga , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Fatores Sexuais , Fatores Sociodemográficos , TaiwanRESUMO
Risk stratification for acute myeloid leukemia (AML) uses molecular and cytogenetic abnormalities identified at diagnosis. Response to therapy informs risk, and morphology continues to be used more frequently than flow cytometry. Herein, the largest cohort of pediatric patients prospectively assessed for measurable residual disease (MRD) by flow cytometry (N = 784) is reported. The "difference from normal" (ΔN) technique was applied: 31% of all patients tested positive (AML range, 0.02% to 91%) after the first course of treatment on Children's Oncology Group study AAML0531. Detection of MRD following initial chemotherapy proved the strongest predicator of overall survival (OS) in univariable and multivariable analyses, and was predictive of relapse risk, disease-free survival, and treatment-related mortality. Clearance of MRD after a second round of chemotherapy did not improve survival. The morphologic definition of persistent disease (>15% AML) failed 27% of the time; those identified as MRD- had superior outcomes. Similarly, for patients not achieving morphologic remission (>5% blasts), 36% of patients were MRD- and had favorable outcomes compared with those who were MRD+ (P < .001); hence an increase in myeloid progenitor cells can be favorable when ΔN classifies them as phenotypically normal. Furthermore, ΔN reclassified 20% of patients in morphologic remission as having detectable MRD with comparable poor outcomes. Retrospective analysis using the relapse phenotype as a template demonstrated that 96% of MRD- patients had <0.02% of the relapse immunophenotype in their end of induction 1 marrow. Thus, the detection of abnormal myeloid progenitor cells by ΔN is both specific and sensitive, with a high predictive signal identifiable early in treatment. This trial was registered at www.clinicaltrials.gov as #NCT00372593.
Assuntos
Leucemia Mieloide Aguda , Criança , Intervalo Livre de Doença , Citometria de Fluxo , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Neoplasia Residual , Estudos RetrospectivosRESUMO
The era of flexible optoelectronics demands development of wearable and bendable structures, foldable touch screens, paper-like displays, and curved and flexible solid-state lighting devices. Here, we demonstrate the fabrication of highly flexible light valves using polymer-dispersed liquid crystal (PDLC) and TiO2/Ag/TiO2 transparent conductive films. TiO2/Ag/TiO2 multilayers were prepared by magnetron sputtering technique on polyethylene terephthalate (PET) substrates at room temperature. By keeping the equivalent TiO2 layers and varying the deposition time of the Ag layer, proper metal nanograins on TiO2 planar plane were formed, providing the best tradeoff between the transmittance, sheet resistance and bending ability. The results are validated by numerical simulations that suggest the best match between the deposition time and individual layer thickness. Based on the performed characteristics of TiO2/Ag/TiO2/PET structures, several flexible light valves are fabricated and characterized. The sheet resistance values of TiO2/Ag/TiO2/PET remain unchanged over 1000 bending cycles. The measured driving voltage and response time values open great potential of TiO2/Ag/TiO2/PET for integration into next-generation ITO-free flexible and stretchable devices.
RESUMO
The rapid generation of strong T cell responses is highly desirable and viral vectors can have potent CD8+ T cell-inducing activity. Immunity to leishmaniasis requires selective T cell responses, with immunization schemes that raise either CD4 or CD8 T cell responses being protective in small animal models. We have defined the leishmaniasis vaccine candidate recombinant fusion antigens, LEISH-F2 and LEISH-F3+, that when formulated in a stable emulsion with a Toll-like receptor (TLR) 4 agonist, induce protective CD4+ T cell responses in animal models as well as providing therapeutic efficacy in canine leishmaniasis and in clinical trials in leishmaniasis patients. We used the genetic sequences of these validated vaccine antigens to design RNA vaccine constructs. Immunization of mice with the RNA replicons induced potent, local innate responses that were surprisingly independent of TLR7 and activated antigen-presenting cells (APC) to prime for extremely potent antigen-specific T helper 1 type responses upon heterologous boosting with either of the subunit vaccines (recombinant antigen with second generation glucopyranosyl lipid A in stable oil-in-water emulsion; SLA-SE). Inclusion of RNA in the immunization schedule also generated MHCI-restricted T cell responses. Immunization with LEISH-F2-expressing RNA vaccine followed later by subunit vaccine afforded protection against challenge with Leishmania donovani. Together, these data indicate the utility of heterologous prime-boost immunization schemes for the induction of potent antigen-specific CD4 and CD8 T cell responses for protection against intracellular pathogens.
Assuntos
Imunidade Heteróloga , Leishmania donovani/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Linfócitos T/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Animais , Linhagem Celular , Citocinas/metabolismo , Feminino , Humanos , Imunização Secundária , Leishmania donovani/genética , Vacinas contra Leishmaniose/genética , Leishmaniose Visceral/prevenção & controle , Ativação Linfocitária/imunologia , Camundongos , NF-kappa B/metabolismo , Transporte Proteico , Linfócitos T/metabolismo , Receptor 7 Toll-Like/metabolismo , Vacinas de Subunidades Antigênicas/genética , Vacinas Sintéticas/imunologiaRESUMO
We propose a prism-hologram-prism sandwiched recording method for the fabrication of polarization-selective substrate-mode volume holograms with a large diffraction angle. In fabrication, the C-RT20 photopolymer is sandwiched between two 45°-90°-45° prisms and the interference fringes can be easily recorded in the recording material. The experimental results are in good agreement with the theoretical predictions. The proposed method features of a reflection-type recording setup for a transmission element and belongs to a technique of longer-wavelength construction for shorter-wavelength reconstruction. In addition, the method is much easier than the traditional recording method of two incident beam interference and has application potential in holographic photonics.
RESUMO
Elderly people are at high risk for influenza-related morbidity and mortality due to progressive immunosenescence. While toll-like receptor (TLR) agonist containing adjuvants, and other adjuvants, have been shown to enhance influenza vaccine-induced protective responses, the mechanisms underlying how these adjuvanted vaccines could benefit the elderly remain elusive. Here, we show that a split H1N1 influenza vaccine (sH1N1) combined with a TLR4 agonist, glucopyranosyl lipid adjuvant formulated in a stable oil-in-water emulsion (GLA-SE), boosts IgG2c:IgG1 ratios, enhances hemagglutination inhibition (HAI) titers, and increases protection in aged mice. We find that all adjuvanted sH1N1 vaccines tested were able to protect both young and aged mice from lethal A/H1N1/California/4/2009 virus challenge after two immunizations compared to vaccine alone. We show that GLA-SE combined with sH1N1, however, also provides enhanced protection from morbidity in aged mice given one immunization (based on change in weight percentage). While the GLA-SE-adjuvanted sH1N1 vaccine promotes the generation of cytokine-producing T helper 1 cells, germinal center B cells, and long-lived bone marrow plasma cells in young mice, these responses were muted in aged mice. Differential in vitro responses, dependent on age, were also observed from mouse-derived bone marrow-derived dendritic cells and lung homogenates following stimulation with adjuvants, including GLA-SE. Besides enhanced HAI titers, additional protective factors elicited with sH1N1 + GLA-SE in young mice were observed, including (a) rapid reduction of viral titers in the lung, (b) prevention of excessive lung inflammation, and (c) homeostatic maintenance of alveolar macrophages (AMs) following H1N1 infection. Collectively, our results provide insight into mechanisms of adjuvant-mediated immune protection in the young and elderly.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Células Dendríticas/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Infecções por Orthomyxoviridae/imunologia , Idoso , Animais , Anticorpos Antivirais/sangue , Células Cultivadas , Células Dendríticas/virologia , Feminino , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Humanos , Imunidade , Imunização , Lipídeo A/farmacologia , Lipídeo A/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Receptor 4 Toll-Like/agonistasRESUMO
BACKGROUND: Several case reports have indicated that tamoxifen induced acute pancreatitis (AP); but no pharmacoepidemiological data support the claim. Therefore, we investigated whether tamoxifen use is correlated with the risk of AP in patients with breast cancer. METHODS: This population-based cohort study used the Taiwan National Health Insurance Research Database. A cohort of 22 005 patients aged ≥20 years with breast cancer from January 1, 2000 to December 31, 2009 was identified and the date of cancer diagnosis was set as the index date. The end point was developing AP during the follow-up. Hazard ratios (HRs) and 95% confidence intervals (CIs) were evaluated to determine the correlation between the risk of AP and tamoxifen use. Because the drug use varied over time, it was measured as a time-dependent covariate in the Cox proportional hazard model. The same approaches were applied in PS-matched cohorts. RESULTS: After adjustment for covariates and medication use including fluorouracil and doxorubicin, the risk of AP was not significant between tamoxifen users and tamoxifen nonusers (adjusted HR = 0.94, 95% CI = 0.74-1.19) in the non-matching cohorts. The results revealed no dose-response trend between tamoxifen use and the risk of AP (adjusted HR = 0.98, 95% CI = 0.96-1.00). The comorbidities DM and gallstones were associated with a significantly increased risk of AP. Similar trends were observed in PS-matched cohorts. CONCLUSIONS: No significant correlation was observed between tamoxifen use and the risk of AP in patients with breast cancer.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Pancreatite/induzido quimicamente , Tamoxifeno/efeitos adversos , Doença Aguda , Idoso , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Taiwan , Tamoxifeno/uso terapêuticoRESUMO
BACKGROUND: Airway exposure to environmental antigens generally leads to immunologic tolerance. A fundamental question remains: Why is airway tolerance compromised in patients with allergic airway diseases? IL-33 promotes innate and adaptive type 2 immunity and might provide the answer to this question. OBJECTIVE: The goal of this study was to investigate the roles played by IL-33 in altering regulatory T (Treg) cells in the lungs and in affecting previously established airway immunologic tolerance. METHODS: We analyzed CD4+ forkhead box P3 (Foxp3)+ Treg cells that were isolated from the lungs of naive BALB/c mice and those treated with IL-33. Airway tolerance and allergen-induced airway inflammation models in mice were used to investigate how IL-33 affects established immunologic tolerance in vivo. RESULTS: CD4+Foxp3+ Treg cells in the lungs expressed the IL-33 receptor ST2. When exposed to IL-33, Treg cells upregulated their expression of the canonical TH2 transcription factor GATA3, as well as ST2, and produced type 2 cytokines. Treg cells lost their ability to suppress effector T cells in the presence of IL-33. Airway administration of IL-33 with an antigen impaired immunologic tolerance in the lungs that had been established by prior exposure to the antigen. Dysregulated Foxp3+ Treg cells with distinct characteristics of TH2 cells increased in the lungs of mice undergoing IL-33-dependent allergen-driven airway inflammation. CONCLUSIONS: IL-33 dysregulated lung Treg cells and impaired immunologic tolerance to inhaled antigens. Established airway tolerance might not be sustained in the presence of an innate immunologic stimulus, such as IL-33.
Assuntos
Hipersensibilidade/imunologia , Interleucina-33/metabolismo , Pulmão/imunologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologia , Imunidade Adaptativa , Alérgenos/imunologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/metabolismo , Humanos , Tolerância Imunológica , Imunidade Inata , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos KnockoutRESUMO
The aim of this study was to assess a possible correlation between zolpidem use and acute pyelonephritis (APN) in women in Taiwan. Therefore, we performed a case-control study involving the Taiwan's National Health Insurance Research Database between 2000 and 2011. This study included 3151 female participants aged 20 to 84 years who experienced the first bout of APN (case group) and 6015 randomly selected female participants without APN (control group). Zolpidem use was defined as "current," "early," or "late," if the last remaining 1 tablet for zolpidem was detected within 7 days, between 8 and 14 days, or ≥15 days before the date of APN diagnosis, respectively. The multivariable unconditional logistic regression model was used to calculate the odds ratios (ORs) with 95% confidence intervals (CIs) to assess the correlation between zolpidem use and APN. After adjusting for confounders, the multivariable analysis yielded an adjusted APN OR of 2.2 for participants with current zolpidem use (95%CI 1.7-2.8) compared with participants who never used zolpidem. The adjusted ORs gradually decreased to 1.4 for participants with early zolpidem use (95%CI 0.8-2.5) and 1.1 for participants with late zolpidem use (95%CI 0.9-1.2), but without statistical significance. Only patients with current zolpidem use had a significantly increased relative risk of APN. Additional large confirmatory studies are needed to illustrate a causal relationship. Meanwhile, physicians and pharmacists should be more cautious about the risk of APN when prescribing and dispensing zolpidem in women.
Assuntos
Hipnóticos e Sedativos/efeitos adversos , Pielonefrite/induzido quimicamente , Piridinas/efeitos adversos , Doença Aguda , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Comorbidade , Feminino , Humanos , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Taiwan/epidemiologia , Fatores de Tempo , ZolpidemRESUMO
TLR ligands are used in modern vaccine adjuvants, TLR4 ligand-based adjuvants are the most advanced in commercial vaccines. Increased understanding of TLR4 receptor-ligand interactions enables chemical synthesis and modification of new leads and our understanding of the biological/immunological mechanisms of combination adjuvants enables formulation of potent and safe vaccine compositions. Characterization of non-glycolipid TLR4 ligands provided new mechanistic information that could lead to new formulations. This review discusses advances in TLR4 agonist design-both glycolipid and non-glycolipid based TLR4 ligands-as well as CD14 activation as options to activate or synergize with TLR4 signaling. Finally, we review the molecular and cellular mechanisms that are elicited by formulated TLR4 targeted combination adjuvants during the initiation of innate immune responses leading to quality adaptive responses.
Assuntos
Adjuvantes Imunológicos , Ligantes , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/imunologia , Vacinas/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Imunidade Adaptativa/imunologia , Animais , Glicolipídeos/síntese química , Glicolipídeos/química , Glicolipídeos/farmacologia , HumanosRESUMO
The transcription factor Runx1 has essential roles throughout hematopoiesis. Here, we demonstrate that Runx1 is critical for T cell maturation. Peripheral naïve CD4(+) T cells from CD4-cre Runx1 cKO mice are phenotypically and functionally immature as shown by decreased production of TNF-α upon TCR stimulation. The loss of peripheral CD4(+) T cells in CD4-cre Runx1 cKO mice is not due to defects in homeostasis or decreased expression of IL-7Rα, as transgenic expression of IL-7Rα does not rescue the loss of CD4(+) T cells. Rather, immature Runx1-deficient CD4(+) T cells are eliminated in the periphery by the activation and fixation of the classical complement pathway. In the thymus, there is a severe block in all aspects of intrathymic T cell maturation, although both positive and negative selection are unaltered. Thus, loss of Runx1 leads to the earliest characterized block in post-positive selection intrathymic maturation of CD4 T cells.
Assuntos
Linfócitos T CD4-Positivos/fisiologia , Diferenciação Celular/fisiologia , Subunidade alfa 2 de Fator de Ligação ao Core/fisiologia , Subpopulações de Linfócitos T/fisiologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Via Clássica do Complemento/fisiologia , Proteínas do Sistema Complemento/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Citometria de Fluxo , Glicosilação , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ácido N-Acetilneuramínico/metabolismo , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Subpopulações de Linfócitos T/metabolismo , Timócitos/citologia , Timócitos/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Single-positive thymocytes that successfully complete positive and negative selection must still undergo one final step, generally termed T cell maturation, before they gain functional competency and enter the long-lived T cell pool. Maturation initiates after positive selection in single-positive thymocytes and continues in the periphery in recent thymic emigrants, before these newly produced T cells gain functional competency and are ready to participate in the immune response as peripheral naive T cells. Recent work using genetically altered mice demonstrates that T cell maturation is not a single process, but a series of steps that occur independently and sequentially after positive selection. This review focuses on the changes that occur during T cell maturation, as well as the molecules and pathways that are critical at each step.
Assuntos
Receptores de Morte Celular/metabolismo , Linfócitos T/citologia , Linfócitos T/fisiologia , Timócitos/citologia , Timócitos/fisiologia , Animais , Diferenciação Celular/imunologia , Divisão Celular , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Seleção Clonal Mediada por Antígeno , Humanos , Transdução de SinaisRESUMO
Recent thymic emigrants are newly generated T cells that need to undergo postthymic maturation to gain functional competency and enter the long-lived naive T cell pool. The mechanism of T cell maturation remains incompletely understood. Previously, we demonstrated that the transcriptional repressor NKAP is required for T cell maturation. Because NKAP associates with histone deacetylase 3 (HDAC3), we examined whether HDAC3 is also required for T cell maturation. Although thymic populations are similar in CD4-cre HDAC3 conditional knockout mice compared with wild-type mice, the peripheral numbers of CD4(+) and CD8(+) T cells are dramatically decreased. In the periphery, the majority of HDAC3-deficient naive T cells are recent thymic emigrants, indicating a block in T cell maturation. CD55 upregulation during T cell maturation is substantially decreased in HDAC3-deficient T cells. Consistent with a block in functional maturation, HDAC3-deficient peripheral T cells have a defect in TNF licensing after TCR/CD28 stimulation. CD4-cre HDAC3 conditional knockout mice do not have a defect in intrathymic migration, thymic egress, T cell survival, or homeostasis. In the periphery, similar to immature NKAP-deficient peripheral T cells, HDAC3-deficient peripheral T cells were bound by IgM and complement proteins, leading to the elimination of these cells. In addition, HDAC3-deficient T cells display decreases in the sialic acid modifications on the cell surface that recruit natural IgM to initiate the classical complement pathway. Therefore, HDAC3 is required for T cell maturation.
Assuntos
Diferenciação Celular , Histona Desacetilases/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismo , Animais , Células da Medula Óssea/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Movimento Celular/genética , Movimento Celular/imunologia , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Histona Desacetilases/genética , Homeostase , Interleucina-7/metabolismo , Contagem de Linfócitos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/imunologia , Timo/imunologia , Timo/metabolismo , Fatores de Necrose Tumoral/metabolismoRESUMO
B lymphopoiesis in bone marrow (BM) is critical for maintaining a diverse peripheral B cell pool to fight infection and establish lifelong immunity. The generation of immature B cells is reduced in Flt3-ligand (FL-/-) mice leading to deficiencies in splenic B cells. Here, we sought to understand the cellular basis of the spleen B cell deficiency in FL-/- mice. Significant reductions in transitional (TS) and follicular (FO) B cells were found in FL-/- mice, and increased frequencies, but not absolute numbers, of marginal zone (MZ) B cells. BAFF-R expression on splenic B cells and serum levels of B cell activating factor (BAFF) was comparable to wildtype (WT) mice. Mixed BM chimeras revealed that the reductions in TS and FO B cells were cell extrinsic. FL administration into FL-/- mice restored the deficiency in TS B cells and normalized the MZ compartment. Ki67 analysis revealed a significant decrease in the proliferative capacity of TS B cells in FL-/- mice. A Bcl2 transgene did not rescue TS cells in FL-/- mice, uncoupling FL-deficiency to Bcl2-dependent survival pathways. Upregulation of CD1d expression and adoptive transfer experiments suggested MZ skewing in FL-/- mice. These findings support an integral role for Flt3 signaling in peripheral B cell maturation.
RESUMO
Recent thymic emigrants (RTEs) must undergo phenotypic and functional maturation to become long-lived mature naive T cells. In CD4-cre NKAP conditional knockout mice, NKAP-deficient RTEs fail to complete T cell maturation. In this study, we demonstrate that NKAP-deficient immature RTEs do not undergo apoptosis, but are eliminated by complement. C3, C4, and C1q are bound to NKAP-deficient peripheral T cells, demonstrating activation of the classical arm of the complement pathway. As thymocytes mature and exit to the periphery, they increase sialic acid incorporation into cell surface glycans. This is essential to peripheral lymphocyte survival, as stripping sialic acid with neuraminidase leads to the binding of natural IgM and complement fixation. NKAP-deficient T cells have a defect in sialylation on cell surface glycans, leading to IgM recruitment. We demonstrate that the defect in sialylation is due to aberrant α2,8-linked sialylation, and the expression of three genes (ST8sia1, ST8sia4, and ST8sia6) that mediate α2,8 sialylation are downregulated in NKAP-defcient RTEs. The maturation of peripheral NKAP-deficient T cells is partially rescued in a C3-deficient environment. Thus, sialylation during T cell maturation is critical to protect immature RTEs from complement in the periphery.
Assuntos
Movimento Celular/imunologia , Proteínas do Sistema Complemento/imunologia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos B/metabolismo , Apoptose/genética , Apoptose/imunologia , Antígenos CD55/genética , Antígenos CD55/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Movimento Celular/genética , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Ativação do Complemento/imunologia , Complemento C3/deficiência , Complemento C3/genética , Complemento C3/imunologia , Proteínas do Sistema Complemento/metabolismo , Expressão Gênica , Imunoglobulina M/imunologia , Imunoglobulina M/metabolismo , Imunofenotipagem , Antígenos Comuns de Leucócito/genética , Antígenos Comuns de Leucócito/metabolismo , Camundongos , Camundongos Knockout , Ácido N-Acetilneuramínico/metabolismo , Fenótipo , Ligação Proteica/imunologia , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/metabolismo , Timo/metabolismoRESUMO
In this study, a novel moiré fringe analysis technique is proposed for measuring the surface profile of an object. After applying a relative displacement between two gratings at a constant velocity, every pixel of CMOS camera can capture a heterodyne moiré signal. The precise phase distribution of the moiré fringes can be extracted using a one-dimensional fast Fourier transform (FFT) analysis on every pixel, simultaneously filtering the harmonic noise of the moiré fringes. Finally, the surface profile of the tested objected can be generated by substituting the phase distribution into the relevant equation. The findings demonstrate the feasibility of this measuring method, and the measurement error was approximately 4.3 µm. The proposed method exhibits the merits of the Talbot effect, projection moiré method, FFT analysis, and heterodyne interferometry.